Patent GB-278228-A (GB)
Title: Improvements in pulp molding apparatus
IPC: D21J5/00
Filed: 1927-01-27
Abstract: 278,228. Folkes, G. E., (Vacuum Pulp Products Corporation). Jan. 27, 1927. Moulding pulp.-Apparatus for moulding dolls' heads &c. from pulp comprises a mould formed in two or more parts 27, 28 which are mounted on members capable of a sliding motion within a mould chamber 12, and a vertically-displaceable base portion 15 co-operating with the mould sections and forming a base section for the mould. The mould chamber 12 is provided with a neck 12 at its lower end to receive the plug portion of the mould base 15, which has perforated lugs 16 sliding on guide rods 17, and the base 15 is held in elevated position by a rod 18 engaging a cam on the base. A perforated mould wall 23, conforming to the shape of the inner face of the base of the moulded article, is supported on mould base 15. The perforated mould sides 27, 28 are carried by horizontal rods 29 sliding through stuffing boxes in the walls of the mould chamber, said rods being carried by brackets 31 slidingly guided at their upper ends on a fixed guide rod 32 and operated by screws 33 provided at the ends of a rotary shaft 35. The shaft 35 is provided with a pinion 36 engaged by a spur gear 37, which is operable by a handle 39 to open or close the mould sides. The pulp is supplied from a gravity-feed tank 7 and a pipe line 10 leads from this tank to an opening 24 in the side of the mould chamber. A three-way valve 40, which is interposed in the pulp-supply line 10, is arranged so that when disposed as in Fig. 5, a through-way connection for the pulp is provided, and this valve may be turned so as to cut off the supply and permit excess pulp to drain back from the mould to a discharge pipe 41. A second three-way valve 42 is also provided in the pipe line, and this is adapted when arranged as in Fig. 5 to form part of the pulp supply conduit, and is also arranged so that it may be turned to shut off such supply and connect the interior of the mould with a compressed air conduit 43. A branch 44 controlled bv a valve 45 opens into the side of the mould chamber. Suction conduits 46, 48 are connected with the bottom and top respectively of the mould chamber, and control valves 47, 49 are provided. The control valve 49 is bye-passed by a pipe 50 and valve 51. A window and illuminating device are arranged in one side of the mould chamber. The mould may be filled by opening the valve 40, but the charging is assisted by suction through any of the pipes 46, 48, 50 or through both the upper and lower pipes 46, 48. When a sufficient thickness of pulp has been obtained, the valve 40 is turned to cut off the supply and drain off the excess pulp, and the valve 42 is operated to shut off the pulp supply and admit compressed air to the chamber through the pipe 43. The compressed air removes excess moisture in the pulp, the valve 47 in the suction conduit 46 at the bottom of the mould chamber being open to carry away such moisture. Moisture from inside the base of the moulded article is removed by a transverse passage 60 in the mould bottom, such passage having other passages extending upwardly into the space beneath the mould wall 23. To free the article from the mould walls, it is subjected to intermittent air pressure, which is accomplished by the action of compressed air admitted to the chamber surrounding the mould through the conduit 44 and a valve in the top of the mould chamber. The latter valve is normally held to its seat by a spring bearing against the underside of a pivoted lever, and operates repeatedly as the pressure accumulates sufficiently to overcome the tension of the spring, and therefore produces a series of shocks on the article. The article is removed by withdrawing the mould sides and lowering the base.